Techniques and Methods
Techniques and Methods
The realities of modelling
There are some people who go to great lengths to get things to the exact likeness of the original -I am not one of those... To me a few millimetres here or there in the working drawing as compared to the highly detailed plans that I have access to -does not bother me. The working drawing is the one that I will construct my model from and depends on what is available to me at that time. I take quite a lot of time with my working drawing as it is this that defines what I have to find to build the model.
Boilers
Boilers are made from lengths of domestic plumbing polypropylene pipe, std sizes for these are: 87mm, 55mm, 30mm and 22mm. The normal size (for me) for a boiler is 55mm. This is a nice size and best of all it took my favourite Electronic Speed Controller and receiver inside -thus keeping all the electronics in a nice dry and insulated environment. The picture below shows a Electronize speed controller (minus case) being introduced to its new home. Steam dome is Kinder Surprise Egg.
Bodywork
I normally work from sheets of 3 mm plywood which I cut to size and then 'Plate' with 60 thous ABS sheet which is bonded to the ply with 2 hour epoxy thinned down to a brushable consistency with alcohol. The following shots show the before and after of the plating process of the Super Golwe. Note Rubber bands and parcel tape are standard methods for holding things while the epoxy sets...
Chassis
Chassis are normally bought from IP Engineering -but there are occasions when I have to build my own. The method I use is very simple consisting of two plates of 1.6mm brass held apart by a combination of 3mm bolts and circuit board spacers (as supplied by Maplins). This shows the bogie for the Climax A clone.
A common problem with home made chassis is getting the motor to power the axles. I bond a hex spacer to the flat side of the motor and then tension it with a rubber grommet and either another piece of brass strip -or a lollipop stick as a transverse 'spring' to hold it onto the gears. The lollipop stick is the more 'springy' and easier to replace -normally this is the method that I use for locos that will have 'small attendants'
The normal method I use is a worm and spur gear setup. There are two main suppliers for these that I use for this. The first is IP Engineering who supply a 16 and 40 to 1 gear set. The second are MFA/Como Drills who have a large selection of motors and gears chains etc etc! They have a large downloadable PDF catalogue and I have found that I have only scratched the surface of their stock...
All IP Engineering wheels, cogs and gears use 1/8 inch axles.
All MFA parts come in 2mm, 3mm, 4mm or 6mm axles.
It is possible to mix and match 3mm and 1/8 inch stuff on the same 1/8 axle -with some care!
IP Engineering are <HERE>
MFA/Como Drills are <HERE>
Suspension
Not everybody has perfect trackwork.... As a builder of articulated locomotives you have the problem of one part of the track being skewed with respect to the next bogie.... I have found that with a simple 0-4-4-0 type locomotive (or carriages) it is better to centrally each bogie in one of two manners.
I either use a cruciform gimbal type pivot or a central rubber grommet pivot. The gimbal approach can be seen in the bogie See Picture 4. The grommet approach uses a large 30mm sealed end grommet from Maplins and a central bolt to the bogie. This gives a rubber suspension not unlike that of early Minis in which Roll Yaw and Pitch factors are converted to damped stretches. I have found that although the gimbal method is neater to look at the grommet method gives a more 'relaxed' ride.
For the longer home made 0-6-0 chassis I have adopted another approach -which is to spring each axle via a trailing lever -not unlike a Citroen 2CV! The V shaped lever comes from a crank set used by model aeroplane makers.
The rubber bands give me some idea of the amount of tension I need to find in my collection of springs (I get a bag of a 100 from Hobbies). The axle pivots on the worm and is held in place by the two end cranks.
